2. On some Points in South-Aerican Geology. By George William Stow, Esq., of Queenstown, South Africa. — Part I.
(Communicated, with Notes, by Professor T. Rupert Jones, F.G.S.)
[Read Nov. 23, 1870*.]
I. On some of the Formations of Port Elizabeth and its neighbourhood.
§ 1. The Jurassic Formations (pp. 497-514).
§ 2. The Posttertiary Formations (pp. 515-522).
III. On the Dicynodon-Formation ; its Forest-zones and other strata (pp. 523-534).
III. The Climatal Changes of South Africa, as indicated by its Geology and Fossils ; and especially the Glacial Denudation of the Karoo Strata (pp. 534-546).
Appendix.
Part I. — § 1. The Jurassic Formations.
Introduction. — Whatever advances geology has made during the last twenty-five years in South Africa (with which the names of Bain, Atherstone, and Rubidge will be ever connected), it must be confessed that we are but mere students in the elementary portion of this part of the great " stone book of nature ; " and it may be expected that every new investigation will bring to light facts, and lead to conclusions, of which at present we have but a feeble and imperfect notion.
To the present time geological knowledge in South Africa has progressed but slowly. The great broad outlines of the geology of the country have been traced by those whose names have been mentioned ; but the minutiae have yet to be filled up. The South- African explorer labours under many serious disadvantages, not only from the horizontal position of many of the strata, but from the want (with the exception of a few mountain-passes) of great road- cuttings, and from the absence of mining operations, so that he has to depend upon the escarpments found along the river-valleys and mountain-sides, leaving large intervening tracts that must still remain in some degree of uncertainty until opportunities shall arise for their more definite examination.
With regard to the fossiliferous strata in the neighbourhood of Port Elizabeth, and of the Zwartkops and Sundays Rivers, for a long time I had felt that too much had been done in the way of curiosity-hunting, by mixing and generalizing all the fossils of what has been termed the " Uitenhage Formation," from whatever part of it they may have come ; thus shells from the upper and lower parts of the Zwartkops River have been massed together, as well as those from the Upper and Lower Sundays River, although many miles intervene between the different localities — a plan that can only lead to a confused idea of the different strata ; and I felt certain that this was one of the causes that prevented just conclusions being arrived at with regard to the formation in question.
As a commencement towards getting more perfect results, I sepa-
- For the other papers read at this meeting see pp. 29-33.
vol. xxvii. — part i. 2 m
